HUNTSVILLE, Ala. — NASA scientist Dr. John M. Horack has been appointed to the Senior Executive Service — the government personnel system covering top managerial positions across some 75 federal agencies — and has been named manager of the Science and Mission Systems Office at NASA’s Marshall Space Flight Center in Huntsville, Ala.

Since December 2005, Horack has served as assistant manager of the Science and Mission Systems Office, handling day-to-day oversight of the organization and its more than 250 civil service and contract employees. The office conducts advanced, complex research at the intersection of science and exploration — expanding general scientific knowledge and understanding, while furthering NASA’s mission to extend our reach across the solar system.

Previously, Horack was assistant director of the Marshall Center’s Space Transportation Programs and Projects Office, supporting management of key space transportation research development activities at the center.

Horack returned to federal service in 2005 after leaving in 2000 to found the Huntsville-based software company Mobular Technologies Inc., for which he served as president, corporate director and chief product architect. The company, which converts customer publications and other print-based assets into Web-based, interactive e-mail applications, serves the financial services, e-commerce and travel and tourism industries.

From 1996-2000, Horack was assistant director for science communications in the Space Sciences Laboratory at the Marshall Center, where he developed new strategies and processes for communicating technical scientific research to non-scientific audiences. In 1999, under Horack’s guidance, the Web-based Science@NASA news site drew more than 200,000 subscribers and won a “People’s Voice” Webby Award for best science site on the Internet. The Webby, awarded annually by the International Academy of Digital Arts and Sciences, is an international award honoring excellence in Web design, creativity, usability and functionality.

From 1994-1995, Horack was assistant mission scientist for the Astro-2 science payload, which flew to space on Space Shuttle Endeavour in March 1995, during the STS-67 mission. The Astro-2 science payload, the second of NASA’s Spacelab missions dedicated to ultraviolet astronomy, made the highest-quality space-based astronomical observations ever recorded in the ultraviolet spectral regions, and successfully detected the presence of intergalactic helium — a test of the “Big Bang” theory of the formation of the universe.

As a Marshall Center gamma ray astrophysics research scientist from 1991-1998, Horack conducted original experiments and theoretical studies in the field of high-energy astrophysics. He was instrumental in groundbreaking research into gamma ray bursts — violent star “hypernovas” that can emit as much energy in 10 seconds as our sun will release in its lifetime.

Horack began his career at NASA in 1987. He was an assembly, test and calibration scientist for the Burst and Transient Source Experiment, or BATSE, one of four science payloads carried on NASA’s Compton Gamma Ray Observatory to study gamma ray bursts. He led scientific testing and calibration activities for BATSE at Marshall before moving to Redondo Beach, Calif., for 16 months as resident scientist for spacecraft integration at prime contractor TRW.

Between January 1990 and April 1991, Horack directed final instrument preparations at NASA’s Kennedy Space Center, Fla., prior to the observatory’s launch on Space Shuttle Atlantis during the STS-37 mission. From 1991 until the Compton Observatory was deorbited in 2000, BATSE scanned the sky for gamma ray bursts, providing NASA with unprecedented insight into the origins and behavior of these unique cosmic events.

Horack, a native of St. Louis, Mo., held internships in 1983 and 1984, respectively, with the St. Louis Cardinals baseball franchise and the sports department at KMOX/CBS Radio in St. Louis.

In 1987, Horack earned a bachelor’s degree in physics and astronomy from Northwestern University in Evanston, Ill. He received a master’s degree in physics in 1992 and a doctorate in that field in 1993 from the University of Alabama in Huntsville.

Horack was a 1998 finalist in NASA’s Astronaut Candidate selection class. He has authored or co-authored more than 75 publications in peer-reviewed journals and for science conferences.

For more information about the Marshall Center’s Science and Mission Systems Office, visit:

http://sms.msfc.nasa.gov/